Inspection of underwater infrastructure, especially in shallow water environments, can be difficult. Shallow water sites (e.g., anything less than or equal to 10 m depth) are difficult to access with sophisticated Diving Support Vessels (DSVs) that are typically used for inspecting underwater pipelines in deeper water with help of tethered divers and/or remotely operated vehicles (ROVs'). Generally, these vessels have a dynamic positioning (DP) system that enables them to stabilize in specific position above the intended targeted inspection sites. A typical DP system only works above 10 m depth of water. Deep water ROVs are equipped with robotic arms and manipulators that can be electrically controlled or using hydraulics and pneumatics. DSVs provide them with electric and mechanical (pneumatic, hydraulics) power, communication, control signals and cleaning fluids (water jet, sand blasting, cavitation jets). As for divers, they are also provided with air, and communication using their umbilical cords tethered to DSVs.
Shallow water environments limit the ability of support vehicles to navigate in close proximity to the structures being inspected. Accordingly, inspection robots need to operate a distance from support vehicles in order to perform inspection and other tasks in these areas. The separation between the support vehicle causes a number of problems with operation of the vehicle, including issues of communication and control over a distance, the need for the robot to travel a distance from the support vehicle to the structure to be inspected, and the ability of the robot to perform inspection and other tasks once the robot is in position.
Accordingly, there is a need to provide underwater vehicles with the means to perform these tasks and an operation method that can be employed to successfully carry out these tasks. Shallow water environment underwater inspection can be achieved according to the present invention as disclosed herein.